This invention relates generally to the field of seismic prospecting and more particularly to a method and apparatus for injecting an acoustic pulse into the earth. In applicant's co-pending, commonly assigned application Ser. No. 83,081 entitled Method And Apparatus For Generating A High Frequency, High Energy Acoustic Pulse, a truck-mounted apparatus is described wherein gas pressure may be employed to propel a guided impact mass downwardly against a rigid target resting on the ground. In order to maximize the kinetic energy of the impact mass at the moment it strikes the target in a device of this character the driving force must also be maximized throughout the downward travel of the mass. Any time delay after activation of such a device during which gas pressure is developing is therefore to be avoided.
It is therefore an object of the present invention to provide an acoustic pulse generator of the type described with improved mass acceleration means.
It is a more particular object of the present invention to provide improved means for applying pressurized gas as an energy source in an acoustic pulse generator of the type described.
Other and further objects and advantages of the invention will become apparent from a consideration of the detailed description and drawings to follow.